1. Field of the Invention
The present invention relates to an inverter, and more particularly to an inverter and a display device including the same.
2. Discussion of Related Art
There have been attempts to integrate a display panel and a driver circuit for driving the display panel in flat panel displays such as an active matrix liquid crystal display or an organic light emitting display.
To date, technologies for the integration of the driver circuit have been mainly focused on designing circuits using CMOS type polysilicon thin film transistors. However, a large number of masks are required to manufacture N-type and P-type transistors at the same time, and additional processes are necessary to adjust each of their threshold voltages. This results in a reduction of process yield and an increase in the process cost, as well as a degradation in the reliability of driver circuits.
In general, it has been known that characteristics of the N-type thin film transistor are more seriously degraded than the P-type thin film transistor since the N-type thin film transistor may be thermally damaged by hot carriers while being driven. Therefore, it is desirable to prevent the driver circuit unit from being degraded because of the N-type elements when the driver circuit unit is designed as a CMOS circuit using polysilicon thin film transistors. For this purpose, an LDD process is additionally used.
Accordingly, additional processes are used to ensure the stability of driving these circuits, and the LDD process itself functions as a factor that may significantly reduce the process yield. Therefore, it may be desirable to design circuits without the use of N-type polysilicon thin film transistors.